maybe the message you are trying to check is wrong. here let me give you an example:
-----BEGIN BITCOIN SIGNED MESSAGE-----
This is Coding Enthusiast and current time is 1474355769
-----BEGIN SIGNATURE-----
1Q9swRQuwhTtjZZ2yguFWk7m7pszknkWyk
IHgdAFlvDvGq+hijJezWWm7MMHaT3P5sVU7hu5Cm9ACIQOkWyPmjdEYKULvRMlJtdDTmGnMvFVDgcm+irLhXqCE=
-----END BITCOIN SIGNED MESSAGE-----
i signed this message:
This is Coding Enthusiast and current time is 1474355769
with this address (with my private key but you only need to know which address):
1Q9swRQuwhTtjZZ2yguFWk7m7pszknkWyk
and the signature is:
IHgdAFlvDvGq+hijJezWWm7MMHaT3P5sVU7hu5Cm9ACIQOkWyPmjdEYKULvRMlJtdDTmGnMvFVDgcm+irLhXqCE=
now click on Tools > Sign/verify message
fill in the boxes with the information above and click verify button.
if the signature is good you will see a messgebox telling you "Signature verified"